Re: [RFC PATCH v2.2 1/7] mm/damon/api: introduce DAMOS_FILTER_TYPE_PROBE_HITS_WSUM

[SJ Park <sj@kernel.org>]

On Fri, 11 Sep 2026 01:20:06 +0000 sashiko-bot@kernel.org wrote:

> Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
> - [Low] The kernel-doc update for `enum damos_filter_type` creates ambiguity regarding the handling of `DAMOS_FILTER_TYPE_PROBE_HITS_WSUM`.
> --
> 
> commit 901df9c4ed650529dec43469f4e3c96f3bf07c6f
> Author: SJ Park <sj@kernel.org>
> 
> mm/damon/api: introduce DAMOS_FILTER_TYPE_PROBE_HITS_WSUM
> 
> This commit updates the DAMON kernel API to introduce a new DAMOS core
> filter type, PROBE_HITS_WSUM. It allows API callers to describe the DAMOS
> action target regions based on their probe_hits weighted sum.
> 
> > diff --git a/include/linux/damon.h b/include/linux/damon.h
> > index 871d26adf6ae5..ef99ff778ae10 100644
> > --- a/include/linux/damon.h
> > +++ b/include/linux/damon.h
> > @@ -399,14 +399,15 @@ struct damos_stat {
> >   * @DAMOS_FILTER_TYPE_UNMAPPED:	Unmapped pages.
> >   * @DAMOS_FILTER_TYPE_ADDR:	Address range.
> >   * @DAMOS_FILTER_TYPE_TARGET:	Data Access Monitoring target.
> > + * @DAMOS_FILTER_TYPE_PROBE_HITS_WSUM:	probe_hits weighted sum range.
> >   * @NR_DAMOS_FILTER_TYPES:	Number of filter types.
> >   *
> > - * All types except &DAMOS_FILTER_TYPE_ADDR and &DAMOS_FILTER_TYPE_TARGET
> > - * are handled by the underlying &struct damon_operations as a part of scheme
> > - * action trying, and therefore accounted as 'tried'.  In contrast,
> > - * &DAMOS_FILTER_TYPE_ADDR and &DAMOS_FILTER_TYPE_TARGET filters are handled
> > - * by the core layer before trying of the action, and therefore not accounted
> > - * as 'tried'.
> > + * All types except &DAMOS_FILTER_TYPE_ADDR, &DAMOS_FILTER_TYPE_TARGET and
> > + * &DAMOS_FILTER_TYPE_PROBE_HITS_WSUM are handled by the underlying &struct
> > + * damon_operations as a part of scheme action trying, and therefore accounted
> > + * as 'tried'.  In contrast, &DAMOS_FILTER_TYPE_ADDR and
> > + * &DAMOS_FILTER_TYPE_TARGET filters are handled by the core layer before
> > + * trying of the action, and therefore not accounted as 'tried'.
> 
> [Severity: Low]
> Does this documentation update leave the handling of
> DAMOS_FILTER_TYPE_PROBE_HITS_WSUM ambiguous?
> 
> The first sentence excludes DAMOS_FILTER_TYPE_PROBE_HITS_WSUM from being
> handled by damon_operations, but the second sentence does not add it to the
> list of filters handled by the core layer. 
> 
> Could the second sentence be updated to explicitly mention
> DAMOS_FILTER_TYPE_PROBE_HITS_WSUM so developers reading the kernel-doc for
> enum damos_filter_type know exactly when its evaluation phase occurs?

The documentation could be improved, but no blocker.  I will consider adding a
reference to the design document which is describing the detail in future.

> 
> [ ... ]
> 
> -- 
> Sashiko AI review · https://sashiko.dev/#/patchset/20260911011330.93678-1-sj@kernel.org?part=1


Thanks,
SJ